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Commit 2a0c5754 authored by Robin Murphy's avatar Robin Murphy Committed by Joerg Roedel
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iommu/of: Refactor of_iommu_configure() for error handling 



In preparation for some upcoming cleverness, rework the control flow in
of_iommu_configure() to minimise duplication and improve the propogation
of errors. It's also as good a time as any to switch over from the
now-just-a-compatibility-wrapper of_iommu_get_ops() to using the generic
IOMMU instance interface directly.

Tested-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 5016bdb7

drivers/iommu/of_iommu.c

+53 −30
Original line number Diff line number Diff line
@@ -96,6 +96,28 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, 
}

EXPORT_SYMBOL_GPL(of_get_dma_window);



static const struct iommu_ops

*of_iommu_xlate(struct device *dev, struct of_phandle_args *iommu_spec)

{

	const struct iommu_ops *ops;

	struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;

	int err;



	ops = iommu_ops_from_fwnode(fwnode);

	if (!ops || !ops->of_xlate)

		return NULL;



	err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);

	if (err)

		return ERR_PTR(err);



	err = ops->of_xlate(dev, iommu_spec);

	if (err)

		return ERR_PTR(err);



	return ops;

}



static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)

{

	struct of_phandle_args *iommu_spec = data;
@@ -105,10 +127,11 @@ static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data) 
}



static const struct iommu_ops

*of_pci_iommu_configure(struct pci_dev *pdev, struct device_node *bridge_np)

*of_pci_iommu_init(struct pci_dev *pdev, struct device_node *bridge_np)

{

	const struct iommu_ops *ops;

	struct of_phandle_args iommu_spec;

	int err;



	/*

	 * Start by tracing the RID alias down the PCI topology as
@@ -123,56 +146,56 @@ static const struct iommu_ops 
	 * bus into the system beyond, and which IOMMU it ends up at.

	 */

	iommu_spec.np = NULL;

	if (of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",

			   "iommu-map-mask", &iommu_spec.np, iommu_spec.args))

		return NULL;

	err = of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",

			     "iommu-map-mask", &iommu_spec.np,

			     iommu_spec.args);

	if (err)

		return err == -ENODEV ? NULL : ERR_PTR(err);



	ops = iommu_ops_from_fwnode(&iommu_spec.np->fwnode);

	if (!ops || !ops->of_xlate ||

	    iommu_fwspec_init(&pdev->dev, &iommu_spec.np->fwnode, ops) ||

	    ops->of_xlate(&pdev->dev, &iommu_spec))

		ops = NULL;

	ops = of_iommu_xlate(&pdev->dev, &iommu_spec);



	of_node_put(iommu_spec.np);

	return ops;

}



const struct iommu_ops *of_iommu_configure(struct device *dev,

					   struct device_node *master_np)

static const struct iommu_ops

*of_platform_iommu_init(struct device *dev, struct device_node *np)

{

	struct of_phandle_args iommu_spec;

	struct device_node *np;

	const struct iommu_ops *ops = NULL;

	int idx = 0;



	if (dev_is_pci(dev))

		return of_pci_iommu_configure(to_pci_dev(dev), master_np);



	/*

	 * We don't currently walk up the tree looking for a parent IOMMU.

	 * See the `Notes:' section of

	 * Documentation/devicetree/bindings/iommu/iommu.txt

	 */

	while (!of_parse_phandle_with_args(master_np, "iommus",

					   "#iommu-cells", idx,

					   &iommu_spec)) {

		np = iommu_spec.np;

		ops = iommu_ops_from_fwnode(&np->fwnode);



		if (!ops || !ops->of_xlate ||

		    iommu_fwspec_init(dev, &np->fwnode, ops) ||

		    ops->of_xlate(dev, &iommu_spec))

			goto err_put_node;



		of_node_put(np);

	while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells",

					   idx, &iommu_spec)) {

		ops = of_iommu_xlate(dev, &iommu_spec);

		of_node_put(iommu_spec.np);

		idx++;

		if (IS_ERR_OR_NULL(ops))

			break;

	}



	return ops;

}



const struct iommu_ops *of_iommu_configure(struct device *dev,

					   struct device_node *master_np)

{

	const struct iommu_ops *ops;



err_put_node:

	of_node_put(np);

	if (!master_np)

		return NULL;



	if (dev_is_pci(dev))

		ops = of_pci_iommu_init(to_pci_dev(dev), master_np);

	else

		ops = of_platform_iommu_init(dev, master_np);



	return IS_ERR(ops) ? NULL : ops;

}



static int __init of_iommu_init(void)